Vacuum attachment for dental aspirator unit



June 30, 1964 H. P. BISHOP VACUUM ATTACHMENT FOR DENTAL ASPIRATOR UNIT 6Sheets-Sheet 1 Filed Sept. 8, 1961 INVENTQR. Ha/mldR Buslwp W k WATTORNEYS June 1964 H. P. BISHOP 3, 3 73 VACUUM ATTACHMENT FOR DENTALASPIRATOR UNIT Filed Sept. 8. 1961 6 Sheets-Sheet 2 INVEN TQR.

Harold/125mm $42040, wfi aaw ATTORNEYS June 30, 1964 Filed Sept. 8. 1961H. P. BISHOP VACUUM ATTACHMENT FOR DENTAL ASPIRATOR UNIT 6 Sheets-Sheet3 INV EN TOR.

Harold Bishop BY F ATTORNEYS H. P. BISHOP June 30, 1964 SPIRATOR UNITVACUUM ATTACHMENT FOR DENTAL A 6 Sheets-Sheet 4 Filed Sept. 8. 1961INVENTQR. HaroldRBwlup BY 9mg 9 & W

ATTORNEYS June 30, 1964 H. P. BISHOP 3,138,873

VACUUM ATTACHMENT FOR DENTAL ASPIRATOR UNIT Filed Sept. 8, 1961 6Sheets-Sheet 5 I24 I20 124a V I 9 I 0: I220 I25 H3 I |25b :22 l "5 I0I27 INVENTOR.

HwroldRBiskop BY 9M0, W8JM ATTORNEYS June 30, 1964 H. P. BISHOP VACUUMATTACHMENT FOR DENTAL ASPIRATOR UNIT 6 Sheets-Sheet 6 Filed Sept. 8,1961 INVENTQR. HwmldP. Buslup BY g wvzqam ATTORNEYS United States Patent3,138,873 VACUUM ATTACHlVlENT FOR DENTAL ASPIRATOR UNIT Harold P.Bishop, 512 W. Gorgas SL, Louisville, Ohio Filed Sept. 8, 1961, Ser. No.136,753 16 Claims. ((11. 32-33) The invention relates to vacuumapparatus for operation of a dental aspirator device. In various dentaltechniques it is necessary that saliva, blood, broken teeth, bone chips,filling material and other debris be removed from the patients mouth.

With present dental practice of excavating teeth by an abrasive slurryblast accompanied by a considerable water supply, it is necessary thatthe abrasive slurry and excess water be rapidly and continuously removedfrom the mouth of the patient during the excavating process.

A primary object of the invention is to provide a motordriven vacuumattachment for a dental aspirator unit having a volume aspiration vacuumdevice and a cup or basin device, valve means for selectively connectingeither the volume aspiration vacuum device or the cup or basin device tothe vacuum attachment, and switch means actuated by said valves forcontrolling the motion of the vacuum attachment.

Another object of the invention is to provide a vacuum attachment of thecharacter referred to comprising a housing, an air inlet for connectionto the dental aspirator unit, an air outlet communicating with amotor-driven fan, and a liquid drain pipe having a trap valve therein.

A further object of the invention is to provide such a vacuum attachmenthaving a porous bag located therein and surrounding the air inlet,whereby broken pieces of teeth, bone chips, filling material and othersolid debris will be received and collected in the bag, while liquidsand air may pass freely therethrough. V

A still further object of the invention is to provide a vacuumattachment of this character having a float therein for automaticallyshutting off the air outlet from the housing to the fan when the liquidlevel in the housing reaches a predetermined level.

Another object of the invention is to provide such a vacuum attachmentin which the motor-driven fan is included therein as a single unit.

A further object of the invention is to provide a vacuum attachment ofthe character referred to with means for attaching the same to aconventional vacuum apparatus.

It is also an object of the invention to provide such a vacuumattachment having means for mounting the motordriven fan forsubstantially noiseless operation.

In general terms, the invention may be briefly described as comprising avacuum attachment for a dental aspirator unit having devices such as avolume aspirator vacuum device, a cup or basin device, or other devicesfor removing blood, saliva, other liquids, broken pieces of teeth, bonechips, filling material or other solid debris from a patients mouthduring a dental operation.

The vacuum attachment comprises a housing defining a chamber having anair inlet connected by a conduit such as a flexible hose to the dentalaspirator unit, an air outlet controlled by a float, a liquid drainoutlet having a trap valve thereon, and a motor-driven fan connected tothe air outlet.

A porous bag is located within the vacuum attachment, surrounding theinlet, for trapping any solid materials, liquid passing through the bagto the bottom of the chamber for later discharge through the liquidoutlet, and air passing through or over the bag to the air outlet andthence to the motor-driven fan.

Manually operated valves in the dental aspirator unit control selectiveconnection of either of the devices there- 3,138,873 Patented June 30,1964 "ice in to the vacuum attachment, and switches actuated by saidvalves control operation of the motor-driven fan.

The above and other objects, apparent from the drawings and followingdescription, may be attained, the above described difiiculties overcomeand the advantages and results obtained, bythe apparatus, construction,arrangement and combinations, sub-combinations and parts which comprisethe present invention, a preferred embodiment of which, illustrative ofthe best mode in which applicant has contemplated applying theprinciple, being set forth in detail in the following description andillustrated in the accompanying drawings.

In the accompanying drawings:

FIG. 1 is a perspective view of a vacuum attachment embodying theinvention, showing the same connected by a flexible hose to a dentalunit;

FIG. 2 is a perspective view of a modified form of the invention;

FIG. 3 is an enlarged, vertical sectional view of the form of the vacuumattachment shown in FIG. 1;

FIG. 4 is a transverse section taken on the line 4-4, FIG. 3;

FIG. 5 is an enlarged bottom plan view of the dental unit;

FIG. 6 is an enlarged, vertical sectional view of the upper portion ofthe vacuum attachment shown in FIG. 3, showing a modified floatarrangement;

FIG. 7 is a fragmentary horizontal sectional view taken as on the line77, FIG. 3;

FIG. 8 is an enlarged, vertical sectional view of the modified form ofthe vacuum attachment shown in FIG. 2; and a FIG. 9 is a view similar toFIG. 8, showing a modified form of float arrangement.

Referring first to the embodiment of the invention illustrated in FIGS.1, 3, 4 and 5, in which similar numerals refer to similar partsthroughout, the apparatus embodying the invention includes the vacuumattachment indicated generally at 1 and the dental aspirator unitindicated generally at 2.

As best shown in FIG. 3, the vacuum attachment includes the upperhousing 3 defining a chamber 3a, for connection to the dental aspiratorunit and having means therein for separating the liquids, solids and airdrawn therethrough from the devices in the dental aspirator unit, thelower housing 4 enclosing the motor-driven fan and provided with meansfor detachably mounting the upper housing 3 thereon.

An air inlet tube 5, preferably downwardly and inwardly disposed, asshown in FIG. 3, is located in the upper end of the housing 3, and asshown in FIG. 1, is adapted to be connected, by a conduit such as theflexible hose 6, with the dental aspirator unit 2.

Within, and located adjacent to one side of the chamber 3a, is provideda vertical tube 7, open at its upper and lower ends and connected at anintermediate point with the inner end of the inlet tube 5.

A bag 8, formed of any suitable porous fabric or the like, is suspendedaround the lower end of the vertical tube 7, as by the supporting hooks9, to receive and trap all solid debris such as pieces of broken teeth,fillings, bone chips and the like, removed from the patients mouth byeither of the devices in the dental aspirator unit and drawn through thehose 6 and inlet tube 5 to the chamber 3a of the vacuum attachment.

This bag being porous, all liquids drawn into the vacuurn attachmentfrom the dental unit will quickly drain therethrough and will becollected upon the concaved bottom wall 10, from which they will laterdrain through the central liquid outlet 11 into the liquid drain pipe12.

A trap valve 13 is provided in the drain pipe 12, the hinged valve gate14 thereof being normally held closed G by suction during operation ofthe vacuum attachment. Below the trap valve 13, the drain pipe 12 leadsto any suitable drain connection such as a sewer or the like.

The upper end of the housing 3 is closed by a detachable cover,comprising the domed top wall 15, the peripheral edge of the coverterminating in the downturned flange 15a seating upon the open upper endof the cylindrical housing 3.

A gasket 16 of suitable material is located between the open upper endof the housing 3 and the cover, and any conventional type of clampingclips 17 are provided upon the upper portion of the housing 3 forengagement over the peripheral portion of the cover for securing thecover to the housing and providing an air-tight seal therebetween.

A baffle 18 depends from the cover adjacent to the vertical tube 7 ofthe inlet means, for the purpose of preventing air discharged throughthe upper open end of the tube 7, and any moisture carried in the air,from being carried across to the other side of the chamber 3a.

The vertical air outlet tube 19 is located through the bottom wall ofchamber 3a, at the opposite side of said chamber from the inlet 5, andextends upwardly into the chamber 311, terminating in the bell 19a. Theair outlet also includes the vertical tube 20, the lower end of which isfitted into the bell 19a of tube 19.

Although a single outlet tube might be used, it is desirable forconvenience of manufacturing and assembling that the outlet comprisesthe separable tubes 19 and 20. A ring 21 is mounted on the upper openend of the tube 20, as by the depending tubular skirt 22 inserted intothe upper end thereof.

An outlet closure valve 23 is provided upon the upper end of the tube20, being hinged to the ring 21 as indicated at 23a. The valve 23 isprovided on its inner surface with a gasket 24 of rubber or the likeadapted to seat upon the valve seat 21a of the ring 21 when the valve isin closed position.

An operating bracket is connected to the valve 23. beyond the pivotpoint 23a, and comprises the outwardly curved, slotted arm 25 and theangular arm 26. For the purpose of operating the valve 23, to close oropen the same as the liquid level rises or falls in the chamber 3a, afloat 27 is provided.

This float may be formed of any suitable material which will float uponwater or similar liquid, and may be of any size or shape desirable ornecessary for performing its required function. For the purpose ofillustration, the float 27 is disclosed as formed of a light weight,nonabsorbent material, preferably cellular foam-like plastic materialcharacterized by a multiplicity of non-communicating cells throughoutits area.

Also for purpose of illustration only, the float 27 is shown as ofcylindrical shape, with a portion of its periphery cut out as at 27a toaccommodate the tubes 19 and 20, but it should be understood that thisis a matter of design only.

A rod 28 is connected to the float 27 and ends upwardly therefrom, beingslidably located through the guides 29, welded or otherwise attached tothe air outlet tube 20. The upper end of the rod 28 is located throughthe slot 25a in the arm 25, and is provided with a suitable head orshoulder 28a of greater dimensions than the width of the slot 25a.

With little or no liquid in the chamber 3a, the float 27 and valve 23will be in the valve open position shown in FIG. 3, the weight of thefloat hanging from the slotted arm 25 holding the valve open as shown.As the liquid level rises in the chamber 3a, the float will rise thereonuntil it reaches the point where the head 28a of the float rod 23contacts the arm 26 and pushes the valve to closed position, seating onthe valve seat 21a and closing the air outlet 19-20. V

A relief valve 33, of any conventional construction, may be mounted uponone side of the housing 3, as by an el- 4t bow 34 which formscommunication with the interior of the housing 3, below the concavedbottom wall 10 therein.

For the purpose of deadening the sound of the motordriven fan,relatively heavy insulation material, such as fibre glass or the like,is attached to the underside of the concaved wall 10, as indicated at35, and to the interior of the side wall of the housing 3, below theconcaved wall 1-3, as indicated at 36.

A substantially channel-shaped annulus 37 is welded, or otherwiseconnected, to the interior of the cylindrical housing 3, at the lowerend thereof and provided with an inturned annular flange 33 with anenlarged central opening 39 therein providing an air outlet from thelower portion of the housing 3.

The lower end of the cylindrical housing 3 is outwardly offset, asindicated at 40, and terminates in the depending annular flange 41adapted to seat upon the inverted U- shape gasket 42 located upon theupper open edge of the lower housing 4.

For the purpose of detachably securing the upper housing 3 to the lowerhousing 4, depending hold-down hooks 43 are located through the angularbrackets 44 upon the exterior of the lower portion of the upper housing3. The lower hooked ends 45 of the members 43 engage the down-turnedhooks 46, welded or otherwise secured to the periphery of the housing 4,adjacent its upper end.

The upper ends of the hook members 43 are threaded, as indicated at 47,to receive thumb nuts 48 by means of which the upper housing 3 may bedetachably clamped to the lower housing 4 to provide an air-tight jointtherebetween.

The lower housing 4 preferably comprises the cylindrical, spaced innerand outer shells 49 and 50 respectively. The outer shell 50 is of lessheight than the inner shell 49, and an inverted U-shape gasket 51 islocated over the upper edge thereof to receive the annularly offsetflange 52 at'the lower end of the curved skirt 53, which is providedwith the upper cylindrical end 54 surrounding the upper end portion ofthe inner shell 49. The gasket 42 is located over the upper end 54 ofthe skirt 53 as well as the upper end of the inner shell 49.

A substantially channel-shaped annulus 56, similar to the annulus 37 butinverted in position, is Welded or otherwise secured within the innershell 49, at a point spaced below the upper end thereof, and terminatesin the inturned annular flange 57. A multiple stage fan 59 is mounted inthe fan housing 60 located between the annuli 37 and 56.

Annular gaskets 61 and 62, of angular cross section, are located betweenthe upper and lower ends of the fan casing 64) and the annuli 37 and 56for providing sounddeadening means for mounting the fan casing and themotor 63 which is attached thereto.

The skirt 53 is clamped upon the upper end of the outer shell 50 bymeans of the legs 64, welded or otherwise secured at their lower ends tothe interior of the shell 50 and attached to the skirt by means ofscrews 65 and nuts 66, which are preferably Tinnerman-type nuts.

A plurality of cushion blocks 67, of rubber or the like, may be attachedto the angular brackets 68 upon the fan housing 60. For this purpose,nuts 69 may be molded within the cushion blocks to receive screws 70located through the brackets 68 and into said nuts.

One of the cushion blocks 67 may be attached to the annulus 56 by meansof a screw 71, having enlarged head 7 2 molded within the lower end ofthis cushion block, a nut 73 being threaded upon the screw 71 on theunderside of the annulus 56. The other cushion blocks 67 merely contactand rest upon the annulus 56, but are preferably not attached thereto.

An air outlet tube 74 is located through the shells 49 and 5th of thelower housing, at a point below the fan housing 61). This outlet may bein the form of a rubber coupling to which an outlet tiibe or hose may beconnected, if desired.

A flat bottom wall 75 is provided for the housing 4, and has thedepending peripheral flange 76 received within and connected to thelower end portion of the shell 50 in any conventional manner.

A circular partition wall 77, preferably formed of insulation materialsuch as fiber glass, is located between the annulus 56 and the bottomwall 75, spaced inwardly from the inner shell 49 of the circular housingso as to form a circular chamber 77a communicating with the air outlettube 74.

An opening 77b is formed in the partition wall 77 at a point opposite tothe outlet tube '7 4, whereby exhaust cooling air passed around themotor 63 by the motor cooling fan 63a may be discharged through theopening 77b into the circular chamber 77a and exhausted through the airoutlet tube 74.

Sound-deadening material such as felt indicated at 75a may be placedupon the top of the flat bottom wall 75. For further deadening the soundof the motor and fan, an annular box 78 depends from the bottom wall 75and has the downwardly domed bottom wall 78a.

Sound-deadening material such as felt is located upon the underside ofthe bottom wall 75 and upon the top of the domed bottom 78a as indicatedat 78b. Air inlet openings 78c are formed in the box 78, and the bottomwall 75 has an air inlet opening 75b therein, whereby air is drawn infrom the outside through the openings 78c and 75b, by the motor coolingfan 63a.

Insulation material such as fibre glass is located upon the inner wallof the outer shell 50 of the lower housing, as indicated at 50a. Anoutlet opening 50b is formed in the lower portion of the outer shell 50and through the adjacent fibre glass lining 50a. An air outlet opening49a is formed in the upper portion of the inner shell 49 adjacent to theexhaust louvers 60a in the lower portion of the multiple stage fanhousing 60.

A vertical bafile wall 79 is located between the inner and outer shells49 and 50 at a point between the outlet openings 49a and 50b as bestshown in FIG. 7. Air is drawn into the multiple stage fan housing 60through the inlet opening 60b in the upper end thereof and is dischargedby the multiple stage fan 59 through the exhaust louvers 60a and throughthe outlet opening 490: in the inner shell 49.

As shown in FIG. 7, the air exhaust through the opening 49a is deflectedby the batlle 79 and caused to travel in the direction of the arrowsentirely around the annular space between the inner and outer shells 49and 5t), being finally discharged from the lower housing through theoutlet opening 50b.

Legs 80 are connected to the bottom wall 75, in any usual and well knownmanner, and may be provided with the inturned lower ends 81 upon whichare located rubber feet 82 for supporting the apparatus upon the floor.

A junction box 85, of conventional design, is attached to the exteriorof the lower housing 4, for making suitable electrical connections tothe motor 63, through a conventional electric .cord 86 leading to apower line, and to the dental aspirator unit 2 through electric cord 87.

Referring now to the dental aspirator unit, indicated generally at 2,and illustrated in detail in FIG. 5, the same may be enclosed in ahousing 88, adapted to be mounted upon any suitable support adjacent tothe dental chair in which the patient is being treated.

A T-coupling 89 is located in the housing, the central tubular leg 90thereof being connected to the flexible hose 6 leading to the air inletof the vacuum attachment. Opposite ends 91 and 91a of the T-coupling areconnected, through conventional shut-oif valves 92 and 92a, with thetubular couplings 93 and 93a.

Flexible hose 94 and 94a are connected to the couplings 93 and 93a forattachment of such devices as a cup or 6 basin 95, or a volume vacuumaspirator 96. When not in use, these devices may be hung upon thesupporting brackets 97 at each end of the housing 88.

Mercury switches 98 and 98a are mounted upon the rotatable valve stems99 and 99a of the valves 92 and 92a respectively, and are connected bywires 100 to the electric cord 87 leading to the motor of the vacuumattachment.

Manually operable handles 101 and 101a are connected to the rotatablevalve stems 99 and 99a of the valves 92 and 92a, for selectively openingand closing each valve, so as to place either of the devices or 96 incommunication with the vacuum attachment through the hose 6.

The longitudinal axes of the rotatable valve stems 99 and 99a areinclined from the horizonal, as shown in FIG. 5, whereby when eithervalve stem is rotated to open position, the corresponding mercury switch98 or 98a carried thereby will be tilted to position to close thecircuit therethrough to the fan motor 63 in the vacuum attachment. Thus,it will be evident that when either valve is opened to connect thecorresponding device 95 or 96 with the vacuum attachment, the motor willbe automatically started.

When not in operation, the parts of the vacuum attachment are normallyin the positions shown in FIG. 3, and the parts of the dental unit arenormally in the positions shown in FIG. 5. In order to operate theapparatus, either valve handle 101 or 101a is moved to open thecorresponding valve 92 or 92a, depending upon which of the devices 95 or96 is to be used.

Upon rotation of the corresponding valve stem 99 or 99a to openposition, the mercury switch 98 or 98a carried thereby will be tilted toclosed position, closing the circuit therethrough to the fan motor 63and starting operation of the multiple stage fan 59.

This immediately creates a suction through the aspirator device 95 or96, as the case may be, and through the corresponding hose 94 or 94a andthrough the opened valve 92 or 92a to the T-coupling 89, thence throughthe flexible hose 6 to the air inlet 5 of the chamber 3a of the vacuumattachment, thence through the vertical tube 19- 20 to the fan 59.

The suction thus created within the housing 3 will immediately pull thehinged gate 14 of the trap valve 13 up to closed position, as shown inbroken lines in FIG. 3, closing the liquid drain outlet 11.

As liquids and bits of solid debris are removed from the patients mouthby either of the devices 95 or 96, as the case may be, they are drawn bysuction through the corresponding hose 94 or 94a, valve 92 or 92a to theT-coupling 89, and then through the flexible hose 6 and into the airinlet 5 of the chamber 3a of the vacuum attachment.

Solid objects are trapped in the porous bag 8, while liquids drainthrough the bag to the bottom wall 10 of the housing 3 and the air willbe drawn through the apparatus to the multiple stage fan 59 as abovedescribed.

When the apparatus is in use for any extended period of time, aconsiderable amount of liquids will accumulate in the chamber 3a, abovethe bottom wall 10 thereof. This condition is aggravated in cases wherethe dentist is excavating teeth by the modern method of feeding a slurryof abrasive material coupled with a water supply, which requirescontinual removal of the slurry and water from the patients month.

As the liquid level rises in the chamber 3a approaching the dangerpoint, the float 27 will be moved up, the rod 28 thereof slidingupwardly through the guides 29 and through the slot 25a in the arm 25until the head 28a thereof strikes the angular arm 26 and swings thevalve 23 to closed position on the valve seat 21a, shutting ofi thesuction, when the motor 63 is shut off.

The hinged gate 14 in the trap valve 13 will drop open by gravity,permitting the liquids to drain out of the chamber 3a through the liquidoutlet 11 and drain pipe 12.

When the liquid has drained from the chamber 3a, the fioat 27 will belowered to open the valve 23, as shown in FIG. 3, and the operation maybe continued as above described.

Reference is now made to the modified form of the invention shown inFIGS. 2 and 8, in which the vacuum attachment is in the form of aseparate unit, the air inlet of which is connected by a conduit, such asa flexible hose, to the dental aspirator unit, and the air outlet ofWhich is connected by a conduit, such as a flexible hose, to aconventional vacuum apparatus.

In FIG. 2, the vacuum attachment to which the invention pertains, isindicated generally at 105, and a conventional vacuum apparatus isindicated generally at 106. The vacuum attachment 105 comprises acylindrical housing 107 having a cover indicated generally at 108 and abottom wall 109, defining a chamber 110.

An air inlet tube 111, preferably downwardly and inwardly disposed asshown in FIG. 8, is located in the upper end of the housing 107, and asshown in FIG. 2, is adapted to be connected by a suitable conduit, suchas the flexible hose 112, to a dental aspirator unit such as indicatedgenerally at 2 in FIGS. 1 and 5.

The air inlet means may be the same as shown in detail in FIG. 3 of thedrawings, and includes the vertical tube 113, open at upper and lowerends and connected at an intermediate point with the inner end of theinlet tube 111.

A porous bag 114, formed of fabric or the like, is suspended around thelower end of the vertical tube 113, as by the supporting hooks 115, toreceive and collect all solid debris, such as pieces of broken teeth,bone chips, filling material and the like, which are removed from thepatients mouth by either of the devices in the dental aspirator unit anddrawn through the hose 112 and inlet means 111413 to the chamber 110 ofthe vacuum attachment.

As above described with reference to FIG. 3, all liquids drawn into thechamber 110 are quickly drained through the bag 114 and will becollected upon the concaved bottom wall 109, from which they may belater drained through the liquid discharge opening 115.

A liquid drain pipe 116 communicates with the liquid discharge opening115, and a trap valve 117, similar to the trap valve 13 shown in FIG. 3,is located in the liquid drain pipe. The hinged valve gate 118, withinthe trap valve 117, will be normally held closed by suction during theoperation of the vacuum attachment.

The cover 108 is domed, as in the form of the invention shown in FIG. 3,and has the peripheral flange 119, seating upon the open upper end ofthe cylindrical housing 107, an air-tight joint being formed by thegasket 120 interposed therebetween. The cover may be clamped upon thehousing by the clamping clips 121.

A tube 122 is located in the chamber 110, the lower end thereof beingconnected to the elbow 123 which extends through one side of thehousing. A valve seat 122a is provided at the upper end of the tube 122,and a valve 124 is hingedly connected thereto and provided with thegasket 124a.

As shown in FIG. 3, and above described, the valve has an operatingbracket attached thereto, comprising the curved, slotted arm 125 and theangular arm 125a. A float 126 has a rod 126a attached thereto andslidably located through the guides 127 and the slotted arm 125 andprovided with a head or shoulder 12521 at its upper end.

The vacuum apparatus indicated generally at 106 in FIG. 2, may be of anyconventional construction, having a fan (not shown) thereon, similar tothe fan shown in FIG. 3, and adapted to be rotated by the electric motor128. A suitable conduit, such as the flexible hose 129, connects the airoutlet 123 of the vacuum attachment 105 to the air intake 130 for thefan in the vacuum apparatus 106. The motor 128 may be connected byflexible electric cord 131 to the mercury switches in the dentalaspirator unit, in the manner shown in FIG. 5.

In the operation of this embodiment of the invention, when either of theaspirator devices of the dental aspirator unit is placed in acommunication with the conduit 112, by operation of the desired valve inthe dental aspirator unit, the corresponding mercury switch in thedental aspirator unit will be closed, starting the motor 128 andoperating the fan in the vacuum apparatus 106.

A suction will thus be created through the conduit 112, air inlet means111113, within the chamber of the vacuum attachment 107, and through theair outlet tube 123 and conduit 129 to the suction fan in the vacuumapparatus 1%.

Liquids and solid debris will be removed from the patients mouth throughthe conduit 112 to the chamber 110. Solid debris will be received andcollected in the porous bag 114, While liquids will pass therethroughand be received in the bottom of the chamber 110, and air will be drawnout of the chamber 110, through the air outlet tube 123 and conduit 129to the intake side of the fan in the vacuum apparatus 106.

The hinged gate 113 of the trap valve 117 will be held up in closedposition, by the suction in the chamber 110, closing the liquid outlet115. As the liquid level in the chamber 110 rises to the predeterminedlevel, the float 126 will be raised closing the valve 124 as abovedescribed with reference to FIG. 3.

As the suction is thus reduced in the chamber 110, and the motor 128 isshut 011?, the hinged gate 118 of the trap valve 117 will drop bygravity, opening the liquid outlet and permitting the liquid to drainfrom the chamber 110. After the liquid has drained out of the chamber110, the float 126 may be returned to the lowered position, as shown inFIG. 8, and the operation of the apparatus may be continued as abovedescribed.

In FIG. 6 is shown the upper housing of an embodiment of the inventionsimilar to that shown in FIG. 3, with a modified form of float and valvearrangement. It should be understood that the remainder of the device isthe same as shown in FIG. 3.

In this embodiment, the upper housing 3' defines a chamber 3", forconnection to the dental aspirator unit. The air inlet tube 5', verticalinlet tube 7' and bag 8' are all the same as illustrated in FIG. 3, anddescribed in detail above. Also, the bottom wall 10', liquid outlet 11'and liquid drain pipe 12, with trap valve therein, are as shown anddescribed with reference to FIG. 3.

The upper end of the housing 3 is closed by a detachable cover,indicated generally at 15', and comprising the flat bottom wall 16' andthe domed top wall 17, forming a plenum chamber 18' therebetween. Theperipheral edge of the cover 15 terminates in the downturned flange 19seating upon the open upper end of the cylindrical housing 3'.

A gasket 20' of suitable material is located between the open upper endof the housing 3 and the cover, and any conventional type of clampingclips 21' are provided upon the upper portion of the housing 3' forengagement over the peripheral portion of the cover for securing thecover to the housing and providing an air-tight seal therebetween.

A centrally disposed tubular member 22' is located through the flatbottom wall 16' of the cover and forms an air outlet from the chamber 3"to the plenum chamber 18 of the cover. A vertical tube 23' has its upperend located through an opening 24 in the flat bottom wall 16 of thecover at one side of the center thereof.

A gasket 25', of rubber or other suitable material, is pressed againstthe underside of the bottom wall 16' of the cover surrounding theopening 24' by a flange 23 on the tube 23, to form an air-tight seal atthis point. The tube 23' extends down through the interior of thehousing 3', the lower end thereof being located through on opening 26 inthe concaved bottom wall 10' and being welded or otherwise connectedthereto as indicated at 27.

.upper end of the housing 107a.

A substantially semi-circular tubular guide 28 is'welded or otherwiseattached at its upper end, as indicated at 29, to the underside of thebottom wall 16' of the cover, surrounding and concentric with thetubular air outlet 22'. A crossbar 30 is connected to the lower end ofthe tubular guide 28' and forms a rest for the cylindrical float 31.

This float is formed of a light weight, non-absorbent material,preferably cellular foam-like plastic material, characterized by amultiplicity of non-communicating cells throughout its area. In order toadjust the weight of the float 31 as desired, any suitable weights maybe connected thereto, such as the metal spikes or nails 32'.

A relief valve 33, of any conventional construction, may be mounted uponone side of the housing 3, as by an elbow 34' which forms communicationwith the interior of the housing 3, below the concaved bottom walltherein.

In FIG. 9 is shown a vacuum attachment of the type shown in FIG. 8 witha modified form of float-operated valve such as shown in FIG. 6. Thevacuum attachment, indicated generally at 105a in this figure, comprisesa cylindrical housing 107a having a cover, indicated generally at 108a,and a bottom wall 109a defining a chamber 110a.

An air inlet tube 111a, preferably downwardly and inwardly disposed asabove described and illustrated, is located in the upper end of thehousing 107a and, as shown in FIG. 2, is adapted to be connected by theflexible hose 112 to the dental aspirator unit indicated generally at 2in FIGS. 1 and 5.

This air inlet means includes the vertical tube 113a open at its upperand lower ends and connected at an intermediate point with the inclinedinlet tube 111a. The porous bag 114a is suspended around the lower endof the tube 113a as by the supporting hooks 115a for the purpose abovedescribed.

A liquid drain pipe 116a communicates with the liquid discharge opening115a, and a trap valve 117a, similar to the trap valve above described,is located in the drain pipe and provided with the hinged valve gate118a.

The cover 108a which normally closes the upper end of the chamber 110ais detachably connected to the open This cover comprises the flat bottomwall 119a and the domed top wall 120a, the peripheral edges of whichterminate in the downturned flanges 121a seating upon the open upper endof the cylindrical housing 107a, an air-tight joint being formed by thegasket 122a interposed therebetween.

An air outlet tube 124a is located entirely through the cover 108aextending downwardly into the chamber 110a and upwardly above the top ofthe cover. The flexible hose 129, as shown in FIG. 2, is adapted toconnect the upper end of the tube 124a to the inlet 130 of the vacuumdevice 106.

A substantially semi-circular tubular guide 125a is attached at itsupper end to the flat bottom wall 119a of the cover surrounding andconcentric with the tubular air outlet 124a. A cross bar 126a isconnected to the lower end of the tubular guide 125a and forms a restfor the cylindrical float 127a which may be of the same construction asthe float 31' in FIG. 6.

From the above it will be obvious that a simple, compact and eflicientvacuum attachment is provided for connection to a dental aspirator unit,with means for automatically operating the vacuum attachment when avalve in the dental aspirator unit is opened.

It will also be apparent that the float in the vacuum chamber of thevacuum apparatus will automatically close the valve when liquid in thechamber approaches the danger point.

Further, it will be seen that when the suction in the vacuum chamber isshut off, and the motor is shut off, the trap valve will automaticallyopen, draining all 10 liquid from the vacuum chamber so thattheoperation of the apparatus may be continued.

It will also be obvious that solid debris and liquids will be separatedfrom each other and from the air, and

separately collected during operation of the apparatus.

Finally, it will be apparent that the motor-driven fan is so mounted andinsulated that it will operate silently.

In the foregoing description, certain terms have been used for brevity,clearness and understanding, but no unnecessary limitations are to beimplied therefrom beyond the requirements of the prior art, because suchWords are used for descriptive purposes herein and are intended to bebroadly construed.

Moreover, the embodiments of the improved construction illustrated anddescribed herein are by way of example, and the scope of the presentinvention is not limited to the exact details of construction.

Having now described the invention or discovery, the construction, theoperation, and use of preferred embodiments thereof, and theadvantageous new and useful results obtained thereby; the new and usefulconstruction, and reasonable mechanical equivalents thereof obvvious tothose skilled in the art, are set forth in the appended claims.

I claim:

1. A vacuum attachment for a dental aspirator unit, comprising a housinghaving a chamber therein, air inlet means and air outlet means for saidchamber, a

.conduit attached to said air inlet means for connecting to a dentalaspirator unit, a motor-driven suction fan, said outlet means includingan imperforate tube providing communication between said chamber and theair intake side of said suction fan, said chamber being adapted toreceive and collect liquids and solid debris drawn through said conduit,liquid outlet means for said chamber, a trap valve in said liquid outletmeans, said 'trap valve being normally closed by the suction in saidchamber, a float in said chamber and valve means operated by said floatfor closing the inlet end of the air outlet tube when liquid in thechamber reaches a predetermined level.

2. A vacuum attachment for a dental aspirator unit, comprising a housinghaving a chamber therein, air inlet means and air outlet means for saidchamber, a conduit attached to said air inlet means for connecting to adental aspirator unit, a motor-driven suction fan, said air outlet meansincluding an imperforate tube providing communication between saidchamber and the air intake side of said suction fan, said chamber beingadapted to receive and collect liquids and solid debris drawn throughsaid conduit, means in said chamber associated with said air inlet meansfor receiving and collecting solid debris and separating it from theliquid and air, liquid outlet means for said chamber, a trap valve insaid liquid outlet means, said trap valve being normally closed by thesuction in said chamber, a float in said chamber and valve meansoperated by said float for closing the inlet end of the air outlet tubewhen liquid in the chamber reaches a predetermined level.

3. A vacuum attachment as defined in claim 1, in which said float isformed of light-Weight, non-absorbent foamlike cellular plasticmaterial.

4. A vacuum attachment as defined in claim 3, in which a weight isconnected to said float for adjusting the weight thereof.

5. A vacuum attachment as defined in claim 1, in which a shut-off valvecontrols communication through said conduit between the dental aspiratorunit and said air inlet means, and an electric switch controllingoperation of the fan motor is operatively connected to said valve sothat opening of said valve automatically closes said switch to operatesaid motor.

6. A vacuum attachment for a dental aspirator unit as defined in claim2, in which said air inlet means comprises a downwardly and inwardlyinclined inlet tube and a vertically disposed tube open at both ends andconnected intermediate its ends to said downwardly and inwardly inclinedtube, and a porous bag is suspended around the lower end of saidvertically disposed tube for receiving and collecting solid debris andseparating it from liquids and air.

7. A vacuum attachment for a dental aspirator unit, comprising housingmeans defining a lower chamber and an upper chamber, there being an airinlet opening in the top of said lower chamber, a suction fan located inthe lower chamber and having its air intake side disposed upwardly, amotor located in the lower chamber and operatively connected to thelower side of said fan, there being an air discharge opening in thelower portion of said lower chamber, air inlet means for said upperchamber, a conduit attached to said air inlet means for connecting to adental aspirator unit, said upper chamber being adapted to receive andcollect liquids and solid debris drawn through said conduit, a cover forsaid upper chamber, an imperforate tubular air outlet member located inthe upper chamber and extending from the upper portion of the upperchamber through the lower end thereof, a valve hingedly mounted at theupper end of said tubu lar member, a bracket upon said valve includingan angular arm and a slotted curved arm spaced therefrom, a float insaid upper chamber, a guide rod upon said float, a guide bracket on saidtubular member through which the guide rod is slidably located, saidguide rod being slidably located through said slotted curved arm andhaving a head for alternate contact with said angular arm and saidslotted curved arm for operating said valve, means providingcommunication between the lower end of said tubular member and theintake side of said fan, and liquid outlet means in the lower portion ofsaid upper chamber.

8. A vacuum attachment for a dental aspirator unit, comprising housingmeans defining a lower chamber and an upper chamber, there being an airinlet opening in the top of said lower chamber, a suction fan located inthe lower chamber and having its air intake side disposed upwardly, amotor located in the lower chamber and operatively connected to thelower side of said fan, there being an air discharge opening in thelower portion of said lower chamber, air inlet means for said upperchamber, a conduit attached to said air inlet means for connecting to adental aspirator unit, said upper chamber being adapted to receive andcollect liquids and solid debris drawn through said conduit, a cover forsaid upper chamber, an imperforate tubular air outlet member located inthe upper chamber and extending from the upper portion of the upperchamber through the lower end thereof, a valve hingedly mounted at theupper end of said tubu lar member, a bracket upon said valve includingan angular arm and a slotted curved arm spaced therefrom, a float insaid upper chamber, a guide rod upon said float, a guide bracket on saidtubular member through which the guide rod is slidably located, saidguide rod being slidably located through said slotted curved arm andhaving a head for alternate contact with said angular arm and saidslotted curved arm for operating said valve, means providingcommunication between the lower end of said tubular member and theintake side of said fan, liquid outlet means in the lower portion ofsaid upper chamber, and a trap valve in said liquid outlet means, saidtrap valve being normally closed by suction in said upper chamber.

9. A vacuum attachment for a dental aspirator unit, comprising housingmeans defining a lower chamber and an upper chamber, there being an airinlet opening in the top of said lower chamber, a suction fan located inthe lower chamber and having its air intake side disposed upwardly, amotor located in the lower chamber and operatively connected to thelower side of saidfan, there being an air discharge opening in the lowerportion of said lower chamber, air inlet means for said upper chamber,

a conduit attached to said air inlet means for connecting to a dentalaspirator unit, said upper chamber being adapted to receive and collectliquids and solid debris drawn through said conduit, a cover for saidupper chamber, said cover being hollow and defining a plenum chambertherein, an imperforate air outlet tube for the top of said upperchamber and communicating with said plenum chamber, an imperforatetubular member extending entirely through said upper chamber andcommunicating at its upper end with said plenum chamber, means providingcommunication between the lower end of said tubular member and theintake side of said fan, liquid outlet means in the lower portion ofsaid upper chamber, vertical guide means in said upper chamber belowsaid air outlet tube, and a float in said vertical guide means forcontacting the lower end of said air outlet tube to close the same whenliquid in said upper chamber reaches a predetermined level.

10. A vacuum attachment for a dental aspirator unit, comprising housingmeans defining a lower chamber and an upper chamber, there being an airinlet opening in the top of said lower chamber, a suction fan located inthe lower chamber and having its air intake side disposed upwardly, amotor located in the lower chamber and operatively connected to thelower side of said fan, there being an air discharge opening in thelower portion of said lower chamber, air inlet means for said upperchamber, a conduit attached to said air inlet means for connecting to adental aspirator unit, said upper chamber being adapted to receive andcollect liquids and solid debris drawn through said conduit, a cover forsaid upper chamber, said cover being hollow and defining a plenumchamber therein, an imperforate air outlet tube for the top of saidupper chamber and communicating with said plenum chamber, an imperforatetubular member extending entirely through said upper chamber andcommunicating at its upper end with said plenum chamber, means providingcommunication between the lower end of said tubular member and theintake side of said fan, liquid outlet means in the lower portion ofsaid upper chamber, vertical guide means in said upper chamber belowsaid air outlet tube, and a float in said guide means for contacting thelower end of said air outlet tube to close the same when liquid in saidupper chamber reaches a predetermined level, and a trap valve in saidliquid outlet means, said trap valve being normally closed by thesuction in said upper chamber.

11. A vacuum attachment for a dental aspirator unit, comprising a lowerhousing, a motor-driven fan located in said lower housing, an upperhousing mounted upon said lower housing, said upper housing comprisingside walls, a bottom wall and a cover defining a vacuum chamber, airinlet means in said vacuum chamber, a vertical imperforate tubecommunicating at its upper end with the upper portion of said vacuumchamber and communicating at its lower end with the intake side of thefan, liquid outlet means in the bottom of said vacuum chamber, meansoperated by suction in the vacuum chamber for closing said liquid outletmeans, a valve hingedly mounted at the upper end of said vertical tube,a bracket upon said valve including an angular arm and a slotted curvedarm spaced therefrom, a float in said vacuum chamber, a guide rod uponsaid float, a guide bracket upon said vertical tube through which saidguide rod is slidably located, said guide rod being slidably locatedthrough said slotted curved arm for operating said valve for closingsaid vertical tube when liquid in the vacuum chamber reaches apredetermined level.

12. A vacuum attachment for a dental aspirator unit as defined in claim11, in which the lower housing comprises spaced shells defining an innerchamber in which the motor-driven fan is located and an outer concentricchamber, air outlet means for the inner chamber, means providingcommunication between the discharge side of 13 the fan and the outerconcentric chamber, and air outlet means for said outer concentricchamber.

13. A vacuum attachment for a dental aspirator unit as defined in claim11, in which said cover is removable and means is provided for formingan air-tight seal between the vacuum chamber and the cover.

14. A vacuum attachment for a dental aspirator unit as defined in claim11, in which an annulus is mounted in the lower end of the upper housingbelow the bottom wall therein, and an annulus is mounted in the lowerhousing at a point spaced below the upper end thereof, and gaskets arelocated between the upper and lower ends of the fan casing and saidupper annulus and lower annulus respectively.

15. A vacuum attachment for a dental aspirator unit as defined in claim14, in which a gasket is located be- 14 tween the lower and upperhousings and means is provided for clamping the lower and upper housingstogether upon said gasket.

16. A vacuum attachment for a dental aspirator unit as defined in claim12, in which sound insulation material is located upon the walls of saidinner and outer chambers, and an insulated box is located upon thebottom of the lower housing and communicates with said inner chamber.

References Cited in the file of this patent UNITED STATES PATENTS2,784,717 Thompson Mar. 12, 1957 2,809,429 Cerveris Oct. 15, 19572,821,021 Winter Jan. 28, 1958

1. A VACUUM ATTACHMENT FOR A DENTAL ASPIRATOR UNIT, COMPRISING A HOUSINGHAVING A CHAMBER THEREIN, A INLET MEANS AND AIR OUTLET MEANS FOR SAIDCHAMBER, A CONDUIT ATTACHED TO SAID AIR INLET MEANS FOR CONNECTING TO ADENTAL ASPIRATOR UNIT, A MOTOR-DIVEN SUCTION FAN, SAID OUTLET MEANSINCLUDING AN INPERFORATE TUBE PROVIDING COMMUNICATION BETWEEN SAIDCHAMBER AND THE AIR INTAKE SIDE OF SAID AUCTION FAN, SAID CHAMBER BEINGADAPTED TO RECEIVE AND COLLECT LIQUIDS AND SOLID DEBRIS DRAWN THROUGHSAID CONDUIT, LIQUID OUTLET MEANS FOR SAID CHAMBER, A TRAP VALVE IN SAIDLIQUID OUTLET MEANS, SAID TRAP VALVE BEING NORMALLY CLOSED BY THESUCTION IN SAID CHAMBER, A FLOAT IN SAID CHAMBER AND VALVE MEANSOPERATED BY SAID FLOAT FOR CLOSING THE INLET END OF THE AIR OUTLET TUBEWHEN LIQUID IN THE CHAMBER REACHES A PREDETERMINED LEVEL.